I'm trying to deploy a WAR as the root application on a Tomcat server. I can manage to do it by adding a line in the server.xml configuration file, but I'd like to externalize that from the server configuration. Note that I also should not modify the WAR in any way.

Documentation seems to indicate that I should be able to do that by adding a ROOT.xml file in ${CATALINA_HOME}/[Engine]/[hostname]/. I tried with the following content :